Dodge claims that the new Challenger SRT Demon will produce a mighty 808 horsepower from the factory on pump gas, with racing gas required to unlock the full advertised 840-horsepower potential. However, after coming across a dynamometer test of a bone-stock Demon on YouTube, we’re starting to suspect that even the more modest number is a tad on the conservative side.
In this video from A2Speed out of Collinsville, Virginia, a factory Dodge Challenger SRT Demon is recorded putting out a peak of 724 horsepower at the rear wheels. Wheel horsepower will always be lower than horsepower as measured at the crankshaft due to driveline losses; the standard estimate for percentage loss on a rear-wheel-drive car is 15 percent. So, knowing that, we can deduce that either the Dodge Challenger SRT Demon has far less than the assumed 15-percent driveline loss (something closer to 10 percent), or it was pushing out roughly 850 horsepower or so at the crank.
Race gas? Who needs it?
Granted, each dynamometer – and each test run – is different, so we can’t assume that this approximately-850-horsepower result can be duplicated on a different machine, on a different day with a different ambient temperature and humidity. But with a margin of about 40 horsepower, we can at least conclude that there’s a rather good chance the SRT Demon’s power is being understated from the factory.
Be sure to watch the dyno test yourself in the video above. If for nothing else, pop on some headphones and do it for the glorious supercharger whine.